REPL

The REPL starts automatically when you run kiwi with no script and stdin is a terminal. You can also start it explicitly with -i or --interactive.

$ kiwi
kiwi 1.4.0 — type 'exit' or press Ctrl+C to quit.
>>

$ kiwi -i
kiwi 1.4.0 — type 'exit' or press Ctrl+C to quit.
>>

Key-value arguments can be passed alongside and will be available inside the session via env::argv():

$ kiwi -name=scotty
kiwi 1.4.0 — type 'exit' or press Ctrl+C to quit.
>> env::argv()
=> {"name": "scotty"}

Expressions are printed automatically

The REPL evaluates each input and prints the result when it is non-null. You do not need println for interactive exploration.

>> 1 + 2
=> 3
>> "hello"
=> "hello"
>> [1, 2, 3]
=> [1, 2, 3]
>> x = 10
=> 10
>> x * x
=> 100

Output from println and other print statements is still written directly — the auto-print only fires when there is a leftover value.

>> println "Hello, World!"
Hello, World!
>>

Multi-line input

Automatic block detection

The REPL detects incomplete blocks automatically. Type the opening line of a block and press Enter — the prompt switches to .. indicating the REPL is waiting for the rest of the block.

>> for i in [1 to 3] do
..   println "i = ${i}"
.. end
i = 1
i = 2
i = 3
>>

This works for all block constructs: for, while, if, fn, struct, try, etc.

Explicit continuation with \

End a line with \ to join it with the next line. The prompt changes to .. as long as continuation is active.

>> for v, i in ["hello", "world"] do \
..   println "${i}: ${v}" \
.. end
0: hello
1: world

Key bindings

Cursor movement

Key	Action
← / →	Move cursor left / right
Home / Ctrl+A	Jump to start of line
End / Ctrl+E	Jump to end of line

Editing

Key	Action
Backspace	Delete character before cursor
Delete	Delete character at cursor
Ctrl+K	Delete from cursor to end of line
Ctrl+U	Delete from cursor to start of line
Ctrl+W	Delete word before cursor

History

Key	Action
↑	Previous history entry
↓	Next history entry (or restore in-progress input)

Exiting

Action	Effect
Type exit or .exit and press Enter	Clean exit
Ctrl+C	Interrupt and exit
Ctrl+D on an empty line	EOF — exits cleanly